Background/Aims Recent evidence has suggested that appendix plays a pivotal role in the development and preservation of intestinal immune system. The aim of this study is to examine whether prior appendectomy is associated with an increased risk for the development of antibiotic-resistant bacteria in bacteremia from biliary tract infection (BTI). Methods Charts from 174 consecutive cases of bacteremia derived from BTI were retrospectively reviewed. Using multivariate analysis, independent risk factors for development of antibiotic-resistant bacteria were identified among the clinical parameters, including a history of appendectomy. Results In total, 221 bacteria strains were identified from 174 BTI events. Of those, 42 antibiotic-resistant bacteria were identified in 34 patients. Multivariate analysis revealed that prior appendectomy (Odds ratio (OR), 3.02; 95% confidence interval (CI), 1.15–7.87; p = 0.026), antibiotic use within the preceding three months (OR, 3.06; 95% CI, 1.26–7.64; p = 0.013), and bilioenteric anastomosis or sphincterotomy (OR, 3.77; 95% CI, 1.51–9.66; p = 0.0046) were independent risk factors for antibiotic-resistant bacteria. Conclusions Prior appendectomy was an independent risk factor for the development of antibiotic-resistant bacteria in bacteremia from BTI.

Totally implantable vascular access devices (TIVADs) are often used to administer chemotherapy by prolonged intravenous infusion. The objective of the present study was to investigate the incidence of long-term complications and identify risk factors associated with TIVAD placement in patients with gastric cancer. A total of 121 patients with gastric cancer who had undergone 150 TIVAD placement procedures for chemotherapy or supportive care were enrolled in the present retrospective cohort study. A number of risk factors were analyzed, including age, sex, hypertension, diabetes mellitus, history of thrombosis, body mass index, disease stage, and site and purpose of TIVAD. In total, 40 TIVADs (26.7%) developed long-term complications, of which 27 (18.0%) were infections, seven (4.7%) were catheter-related deep vein thrombosis (CR-DVT), and six (4.0%) were obstructions. Chemotherapy was associated with an increased rate of infectious adverse events (odds ratio 2.925; 95% CI, 1.104–7.750; P=0.031) according to the multivariate analysis. CR-DVT occurred more frequently in upper arm ports than in chest wall ports; however, this difference was not statistically significant (7.5 vs. 0.0%; P=0.084) according to the univariable analysis. All CR-DVTs developed in the upper arm sites. Chemotherapy and the upper arm site were associated with long-term complications in patients with TIVAD. However, further studies are needed to confirm the findings of the present study and to determine the reasons for the high incidence of long-term complications in these patients.

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Introduction: Endoscopic submucosal dissection (ESD) is an advanced therapeutic technique for en bloc resection of superficial gastrointestinal neoplasms. Although gastric ESD is minimally invasive and provides favorable outcomes, it is technically difficult and requires a long procedure time for dissection. The traction-assisted approach overcomes some of the difficulties of gastric ESD, but its ability to reduce the procedure time remains unclear. The traction-assisted approach using dental floss and a clip did not reduce procedure time in the total population, but it reduced procedure time for lesions limited to the greater curvature of the upper or middle of the stomach. Although the traction direction of the clip-with-line method may be limited to the oral side via the cardia, EndoTrac ESD may provide flexible traction at any time during the procedure. This prospective randomized control study has been designed to compare the efficacy and safety of EndoTrac and conventional gastric ESD.Methods/design: This multicenter, randomized control trial will enroll 150 patients at 2 hospitals in Japan undergoing EndoTrac or conventional ESD for gastric epithelial neoplasia. Patients with a single gastric epithelial neoplasm who meet the inclusion and exclusion criteria will be randomized to EndoTrac or conventional ESD. Patients will be randomized by a computer-generated random sequence with stratification by operator experience, tumor size, tumor location, and institution. The primary endpoint will be ESD procedure time, defined as the time from the start of the submucosal injection to the completion of resection. Other outcomes will include the rates of adverse events and pathological curability Discussion: The ability of EndoTrac ESD to reduce the long procedure time and/or adverse events observed with conventional ESD can not only reduce physical stress on the patient, but can also reduce length of hospital stay and medical costs. Reduced technical difficulty will contribute to the widespread adoption of this ESD technique worldwide.

Background Peritoneal metastasis (PM) in gastric cancer (GC) is characterized by diffusely infiltrating and proliferating cancer cells accompanied by extensive stromal fibrosis in the peritoneal space. The prognosis of GC with PM is still poor regardless of the various current treatments. In order to elucidate the cause of difficulties in PM treatment, we compared the tumor immune microenvironment (TME) in primary and PM lesions in GC. In addition, a PM model with fibrous stroma was constructed using immunocompetent mice to determine whether its TME was similar to that in patients. MethodsImmuno-histochemical analyses of infiltrating immune cells were performed in paired primary and PM lesions from 28 patients with GC. A C57BL/6J mouse model with PM was established using the mouse GC cell line YTN16 either with or without co-inoculation of mouse myofibroblast cell line LmcMF with a-SMA expression. The resected PM from each mouse model was analyzed the immunocompetent cells using immunohistochemistry.ResultsThe number of CD8+ cells was significantly lower in PM lesions than in primary lesions (P<0.01). Conversely, the number of CD163+ cells (M2 macrophages) was significantly higher in PM lesions than in primary lesions (P=0.016). Azan staining revealed that YTN16 and LmcMF co-inoculated tumors were more fibrous than tumor with YTN16 alone (P<0.05). Co-inoculated fibrous tumor also showed an invasive growth pattern and higher progression than tumor with YTN16 alone (P=0.045). Additionally, YTN16 and LmcMF co-inoculated tumors showed lower infiltration of CD8+ cells and higher infiltration of M2 macrophages than tumors with YTN16 alone (P<0.05, P<0.05). These results indicate that LmcMF plays as cancer-associated fibroblasts (CAFs) by crosstalk with YTN16 and CAFs contribute tumor progression, invasion, fibrosis, and immune suppression.ConclusionsThis model is the first immunocompetent mouse model similar to TME of human clinical PM with fibrosis. By using this model, new treatment strategies for PM, such as anti-CAFs therapies, may be developed.

Background Peritoneal metastasis (PM) in gastric cancer (GC) is characterized by diffusely infiltrating and proliferating cancer cells accompanied by extensive stromal fibrosis in the peritoneal space. The prognosis of GC with PM is still poor regardless of the various current treatments. In order to elucidate the cause of difficulties in PM treatment, we compared the tumor immune microenvironment (TME) in primary and PM lesions in GC. In addition, a PM model with fibrous stroma was constructed using immunocompetent mice to determine whether its TME was similar to that in patients. Methods Immuno-histochemical analyses of infiltrating immune cells were performed in paired primary and PM lesions from 28 patients with GC. A C57BL/6J mouse model with PM was established using the mouse GC cell line YTN16 either with or without co-inoculation of mouse myofibroblast cell line LmcMF with a-SMA expression. The resected PM from each mouse model was analyzed the immunocompetent cells using immunohistochemistry.Results The number of CD8+ cells was significantly lower in PM lesions than in primary lesions (P<0.01). Conversely, the number of CD163+ cells (M2 macrophages) was significantly higher in PM lesions than in primary lesions (P=0.016). Azan staining revealed that YTN16 and LmcMF co-inoculated tumors were more fibrous than tumor with YTN16 alone (P<0.05). Co-inoculated fibrous tumor also showed an invasive growth pattern and higher progression than tumor with YTN16 alone (P=0.045). Additionally, YTN16 and LmcMF co-inoculated tumors showed lower infiltration of CD8+ cells and higher infiltration of M2 macrophages than tumors with YTN16 alone (P<0.05, P<0.05). These results indicate that LmcMF plays as cancer-associated fibroblasts (CAFs) by crosstalk with YTN16 and CAFs contribute tumor progression, invasion, fibrosis, and immune suppression.Conclusions This model is the first immunocompetent mouse model to accurately reflect the similar to TME of human clinical PM with fibrosis. By using this model, new treatment strategies for PM, such as anti-CAFs therapies, may be developed.

Duodenal gastrointestinal stromal tumors (D-GISTs) are uncommon and account for 3–5% of all GISTs. Currently, no established surgical strategy for D-GISTs exists, which mostly depends on tumor size, relation to the ampulla and invasion of the adjacent organ. We report a case of large D-GIST resected by robotic distal gastrectomy. A 62-year-old woman was diagnosed with a 5-cm D-GIST located at posterior wall of the duodenal bulb. Computed tomography findings indicated possible tumor invasion of the pancreas head. Robot-assisted distal gastrectomy was firstly planned and pancreatoduodenectomy was also considered when the tumor was invading to the pancreas. Although tumor was tightly adherent to the pancreas, it could be dissected from the pancreatic head without capsule damage and resected by robotic distal gastrectomy with no postoperative complication. The large D-GIST tightly adherent to the pancreas could be resected by efficiency of the robotic surgery.

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